1. Field of the Invention
The present invention relates to adapters to connect a television camera to a microscope and more particularly to such an adapter for connecting a surgical microscope to a television camera.
2. Related Art
At the present time a number of adapters are commercially available to connect a television camera to a microscope. Generally the television camera is small and uses a solid-state electronic imaging device, such as a CCD (Charge Coupled Device). The microscope may be a stereo bright field microscope. Such adapters are available from leading scientific and surgical microscope manufacturers including Nikon, Leica-Wild and Zeiss.
When surgical stereomicroscopes are used for certain types of surgery, such as surgery on the ear, nose, throat, brain, spinal cord and eye (especially retina surgery) and other types of microsurgery, it is important that the exact location of interest be centered in the field of view of the image plane of the television camera and that the TV image be in focus. The TV image is displayed on a monitor and may be viewed by the operating surgeon, other members of the surgical team and students.
For example, if the point of surgical interest is a portion of a patient's retina and it is off-center or out of focus, or even so far off-center to be off the monitor's screen, the displayed image may be confusing or misleading. In many critical surgical operations it is important that the image on the monitor screen is on-center and in-focus.
U.S. Pat. No. 5,052,789 shows a television camera connected to a stereoscopic microscope. The optical path to the camera includes a pair of prisms and focusing lenses. However, there is no disclosure of a centering mechanism or how the focusing lenses are controlled.
U.S. Pat. No. 5,002,376 at FIG. 2 shows a surgical stereomicroscope having a zoom tube for a camera 70. U.S. Pat. No. 4,277,130 discloses a zoom lens system for a camera in a stereomicroscope.